Scaffolds



May 8, 1956 J. s. MODONOUGH SCAFFOLDS Filed May 27, 1952 FIG! INVENTOR.JAMES S. MCDONOUGH HTTORNEY United States Patent Ofice 2,744,795Patented May 8, 1956 SCAFFOLDS James S. McDonough, Hartford, Ill.;Herbert E. McDonough, James E. McDonough, and F. Marvin McDonough,administrators of said James S. McDonough, deceased, assignors to TheFinest Scaffold Co., Belleville, 11]., a corporation of DelawareApplication May 27, 1952, Serial No. 290,256

2 Claims. (Cl. 304--2) This invention relates in general to scaffoldsand, more particularly, to certain new and useful improvements inlocking means for preventing unauthorized dislodgment of transversesupport members during use of the scaffold.

It is the primary object of the present invention to provide a scaffoldhaving cooperative means associated with the standards and thetransverse members which are adapted for locking engagement uponimposition of weight, such as of a workman, on the transverse members oron a platform supported thereby; and which, upon removal of the weightfrom the scaffold will revert to unlocked relation.

It is a further object of the present invention to provide scaffoldlocking means which are positive in operation and which are certain tobe in engaged position during actual use of the scaffolding.

It is a still further object of the present invention to provide ascaffold which is adjustable vertically and horizontally and which maybe adjusted with maximum facility.

It is an additional object of the present invention to provide ascaffold which has a simplicity of parts; which may be mostinexpensively manufactured and which is reliable and durable in usage.

With the above and other objects in view, my invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims.

In the accompanying drawing- Figure l is an elevational view of ascaffold constructed in accordance with and embodying the presentinvention;

Figure 2 is a fragmentary perspective view of the scaffold;

Figure 3 is a transverse sectional view taken along line 33 of Figure 2;and

Figure 4 is a transverse sectional view taken substanstantially alongline 33 of Figure 2, showing the cross beam in locked position.

Referring now to the drawing which illustrates a preferred embodiment ofthe present invention, A indicates a scaffold incorporating a pair ofstandards or uprights 1, 1', each of which comprises a verticallyextending channel member 2, preferably of steel, having its legs or sideflanges 3, 3', directed inwardly with its web 4 presented to the outerside. Each channel 2 is supported at its lower end by leg braces 5, 5,the lower ends of which are suitably secured as by riveting, to anangle-shaped base member 6, axially normal to the channel member 2. Theside flanges 3, 3, of the channel members 2 are each drilled atpredetermined intervals, such as 6 inches substantially throughout theirextent to provide pairs of aligned apertures, generally denoted 7, 7,for receiving a bolt or pin 8 extending transversely between the flanges3, 3', and rigidly maintained in position by appropriate means.

Provided for transverse or bridging disposition between the standards 1,1', is a pair of cross beams or members 9, 10, commonly referred to asstringers, which are preferably fabricated of sturdy wood, such as fir,and

in size comparable to the conventional 2" x 6". Said beams 9, 10, aredisposed adjacent their inner ends in side by side relation, beingsupported therein by means of a plurality of brackets 11 bolted spacedlyon said beams 9, 10; said brackets 11 permitting relative slidablemovement of the beams 9, 10, for mutual extension or contraction toaccommodate the selected distance between the standards 1, 1'.

On the upwardly and downwardly presented surfaces of each of the beams9, 10, at their outer ends, there is secured as by carriage-type bolts12, strap members 13, 13', respectively, which extend beyond the outerend faces of the beams 9, 10, and spacedly therefrom are bent downwardlyin hook formation to provide depending tongues 14, 14. The apertures 7,7, in the channel members 2 are located with reference to the inner faceof the web 4 so that the distance between the bolts 8 and the web 4 isslightly in excess of the thickness of the tongues 14, 14', which arepreferably of inch metal.

In usage, the standards 1, 1', are presented in spaced apart relationwith the distance therebetween depending upon the particular work to beaccomplished. The beams 9, 10, are commensurately extended and arepresented for insertion of the depending tongues 14, 14', downwardlybetween the web 4 and vertically adjacent bolts 8, as may best be seenin Figure 3. Since the space between the bolts 8 and the web 4 is butslightly greater than the thickness of the tongues 14, 14', it isrequisite that the beams 9, 10, be held in substantially horizontalposition during the insertion step to prevent any impeding contactbetween the tongues 14, 14, and the web 4. The plurality of verticallyaligned bolts 8 in each standard 1, 1', permit vertical adjustability ofthe beams 9, 10, so that scaffold boards or a platform 15 supportedthereon may be conveniently positioned with reference to the work. Anydesired number of the scaffolds A herein described may be used tosupport a platform 15 adequate for the particular working area.

When the scaffold A is in usage with a workman or workmen on theplatform 15, the beams 9, 10, will be subjected to a downwardly directedforce due to the weight of the workman or workmen which force istransmitted directly from the platform. This force will cause the beams9, 10, to cant or to tilt downwardly at their inner ends, which, asindicated above, are not supported by any external means. This cantingmovement will cause a relative upward rocking of the outer end portionsof the beams 9, 10, with the tongue 14' being brought into surfaceabutting relation with the inner face of the Web 4 (see Figure 4). Uponsuch surface engagement further canting or tilting of the beams 9, 10,is prevented and the same are thereby positively held against untowarddislodgment. The tongues 14, 14, are stable and are resistant to anydeformation by such tight locking engagement with the web 4. It willthus be seen that the lock-actuating force is the weight of the workmanor workmen on the platform 15, whereby whenever the scaffold A is inuse, the beams 9, 10, will be locked. By this invention, the security ofthe workmen is certain since there is no need of any conscious lockingprocedure as would be required with various types of latches and thelike heretofore well known in this art. The workmen may thus move acrossthe platform 15 without concern as to the safety of the scaffold A sincehis very presence on thesaid platform assures locking engagement.

When the scaffold A is not in use, the absence of any weight upon thebeams 9, 10, will permit same to return to normal horizontal dispositionwith the tongues 14, 14', reverting to the original position as shown inFigure 3. I

In view of the foregoing, it will be readily seen that the scaffold Acomprises but few parts which may be easily assembled and disassembledwithout the exercise of skill on the part of the user. Additionally, thecomponent parts are so designed as to. require a minimum of storagespace when the scaffold A is disassembled and. which are relativelylight in weight for facile transportability.

It should be understood that changes and modificain the form,construction, arrangement, and combination of the several parts of thescaffold may be made and substituted for those herein shown anddescribed without departing from the nature and principle of the presentinvention.

What I claim and desire to secure by Letters Patent 1. A scaffoldcomprising a pair of spaced apart, vertically presented channel members,each channel member having side flanges and a web, a plurality ofvertically aligned, spaced bolts extending transversely between the sideflanges of each channel substantially throughout its length, a beam, andvertically spaced bolt-engaging members secured on the upper and lowersurface of said beam at each of its ends, said bolt-engaging members ateach end having. vertical depending tongue-like portions at theirextremities for downward insertion between a bolt and the channel web ofthe adjacent channel member for normal disposition in planar parallelrelation to the channel web, the tongue-like portion of the lowermosthook member projecting downwardly below the beam, said bolts beingspaced from the channel web a distance slightly greater than thethickness of the depending portions of the bolt-engaging members wherebythe same will normally be spaced therefrom and upon the imposition ofweight on the beam the depending portion of at least one of said membersat each end of the beam will be moved into lockingly abutting relationwith the adjacent channel web, said members having a width less than thedistance between the channel side flange for being normally spacedtherefrom.

2. A scaifold comprising a pair of spaced apart, vertically presentedchannel members, each channel memher having side flanges and a web, aplurality of vertically aligned, spaced bolts extending transverselybetween the side flanges of each channel substantially throughout itslength, a pair of strap members secured respectively on the upper andlower surface of said beam adjacent each of its ends and each having ahorizontal portion projecting beyond the adjacent end of the beam forresting disposition upon a bolt, said strap members each further havingat the outer end of its horizontal portion a downwardly bent tongueportion for downward insertion between a bolt and a channel web of theadjacent channel member, the tongue-like portion of the lowermost hookmember projecting downwardly below the beam, said bolts being spacedfrom the channel web a distance slightly greater than the thickness ofthe tongue portions of the strap members whereby the same will normallybe spaced therefrom and upon imposition of weight on the beam the tongueportion of the lower strap member at each end of the beam will be rockedin a tight surface abutting relation with the adjacent channel web, saidstrap members having a width less than the distance between the channelside flange for being normally spaced therefrom.

References Cited in the file of this patent UNITED STATES PATENTS118,424 Barlow Aug. 29; 1871 118,553 Redick Aug. 29, 1871 153,270Newhard July 21, 1874 405,195 Aryes June 11, 1889 768,295 Palfrey Aug.23, 1904 843,456 Higbee et al. Feb. 5, 1907 924,353 Horton June 8, 19092,549,212 Lane Apr. 17, 1951

